import pgzrun

def draw():
    #     screen.fill('white')
    #     screen.draw.circle((400, 300), 10, 'black')
    #     screen.draw.circle((400, 300), 20, 'black')
    #     screen.draw.circle((400, 300), 30, 'black')
    #     screen.draw.circle((400, 300), 40, 'black')
    #     screen.draw.circle((400, 300), 50, 'black')

    screen.fill('white')
    for r in range(1, 201, 10):
        screen.draw.circle((400, 300), r, 'black')

    #     screen.fill('white')
    #     for r in range(250, 0, -50):
    #         screen.draw.circle((400, 300), r, (255,0,0))

    # 彩色同心圆
    #     screen.fill('white')
    #     for r in range(250, 0, -10):
    #         screen.draw.filled_circle((400, 300), r,
    #                                   (random.randint(0, 255), random.randint(0, 255),
    #                                    random.randint(0, 255)))

    # 蓝色连接
    #     screen.fill('white')
    #     for x in range(R, 800, 2*R):
    #         screen.draw.filled_circle((x, 300), R, 'blue')

    # 蓝色铺满
    #     screen.fill('white')
    #     for y in range(R, 600, 2*R):
    #         for x in range(R, 800, 2*R):
    #             screen.draw.filled_circle((x, y), R, 'blue')

    # 黑色粗圆
    #     screen.fill('white')
    #     for r in range(250, 0, -50):
    #         screen.draw.filled_circle((400, 300), r, 'black')
    #         screen.draw.filled_circle((400, 300), r-25, 'white')

    # 带光圈
    #     screen.fill('white')
    #     for r in range(255, 0, -1):
    #         screen.draw.filled_circle((400, 300), r, (255-r, 255-r, 0))

pgzrun.go()